Tag Archives: Chennai

It has been an interesting week at village – dry weather, (ultra) dry classes, (boring) external seminars and more of depressing environment but one can always find some hope out of such depressing environment. Overall life here is colourful but one just needs to lookout for colours. 🙂

One interesting case to report today – F root server has quite bad connectivity in India. Last week a friend asked me for traceroutes to all root servers and here’s what I saw when I did traceroute for F root from BSNL connection:

Quick look at F root server:

F root uses 192.5.5.241 across all anycasting instances and in India this block is being announced by Autonomous System Number 24049 which is of ISC. AS24049 does a BGP announcement for 203.119.18.0/24 at NIXI Chennai and this is “supposed to be” taken by all ISPs participating at Chennai IXP.

When I requested my friends across India for traceroutes to F root, it was a very interesting result!

We found connectivity works from everyone including BSNL too for people living in or near around Chennai.

Here we can see hop 4 is core network of BSNL while hop 5 is NIXI Chennai and hop 6 is ultimately F root server.

Initially I got feeling that this is because of broken IGP implementation for BSNL network since their border gateway routers are holding different routing tables and they are not syncing them properly but one strange thing here – Hop 4 in this traceroute i.e 218.248.250.142 is same as last hop in 1st traceroute (done from BSNL Haryana). How come same router has no route when looked from Haryana while it works for Chennai (and nearby) users!

This gives clue that forward path is there but return path has issues. For some reason ISC router in NIXI Chennai is not able to get return path to reply for non-Chennai region users.

I raised this concern with Network Operations Center of ISC yesterday along with mailing lists like APNIC & RIPE Atlas. One of my friend who is expert into these issues pointed us to right direction which is NIXI routing policy.

Reading out policy:

” An ISP at any NIXI node must at a minimum announce all its regional routes to the NIXI router at that NIXI location. All ISPs connecting to that NIXI node are entitled to receive these routes using a single BGP session with the NIXI router. This will guarantee the exchange of regional traffic within a NIXI node. This is referred to as forced regional multi-lateral peering under the policy”

So this is what is happening:

Each operator is providing ISC with limited regional routes around Chennai area and not to it’s entire network. This was later confirmed by ISC NOC reply. This is sort of awful situation in terms of policy which is breaking India backbones badly and ISPs not able to even reach root servers instances hosted within country. Worst, I have been told that there is 10 day time for fix of this problem else ISC is prepared to pull off plug from Chennai F root node. Since it’s anycasting, once there won’t be any instance inside India injecting routes, traffic will simply start flowing towards other F root server instances in nearby countries. If this happens, it will be surely a sad thing for India since we will loose one out of threefour root nameservers. 🙁

With hope that next update on this issue will be positive, time to end this post for now. Feel free to share your comments below.

(Incase your are ISP or datacenter in India – I would be happy to discuss this issue with you. You can contact me directly from here)

***Updates***

ISC Network Operations Center acted very efficiently on this issue. Special thanks to Mr Leo Bicknell from ISC who is taking care of it. In initial phase full routing table was made available to F root server via STPI Internet transit. This fixed the problem (on test basis) and after a week of testing, F root instance in Chennai has been switched off until ISC & NIXI get into a contract over additional bandwidth and costs.

For now Indian traffic is being routed to other anycasting instance of F root. Earlier it was California, US instance and now it is Hong Kong instance.